Pure bound field corrections to the atomic energy levels and the proton size puzzle

Abstract

Reinforcement of the puzzle about the proton charge radius, rE, stimulated by the recent experiment with muonic hydrogen (Antognini et al. Science, 339, 417 (2013)) induced new discussions on the subject, and now some physicists are ready to adopt the exotic properties of the muon, lying beyond the Standard Model, to explain the difference between the results of muonic hydrogen experiments (rE = 0.840 87(39) fm) and the CODATA-2010 value rE = 0.8775(51) fm based on electron–proton scattering and hydrogen spectroscopy. In the present contribution we suggest a way to achieve progress in the entire problem via paying attention on some logical inconsistency of fundamental equations of atomic physics, constructed by analogy with corresponding classical equations without, however, taking into account the purely bound nature of electromagnetic fields generated by the electrically bound particles in stationary energy states. We suggest eliminating this inconsistency via introducing some appropriate correcting factors into these equations, which explicitly involve the requirement of total momentum conservation in the system “bound particles and their fields” in the absence of electromagnetic radiation. We further show that this approach allows us not only to eliminate long-standing discrepancies between theory and experiment in the precise physics of simple atoms, but also yields the same estimation (though with different uncertainties) for the proton size in the classic 2S–2P Lamb shift in hydrogen, 1S Lamb shift in hydrogen, and 2S–2P Lamb shift in muonic hydrogen, with the mean value rE = 0.841 fm. Finally, we suggest the crucial experiment for verification of the validity of pure bound field corrections: the measurement of decay rate of bound moun in various meso-atoms, especially at large Z, where the standard calculations and our predictions essentially deviate from each other, and some of the available experimental results (Yovanovitch. Phys. Rev. 117, 1580 (1960)) strongly support our approach.